由於近年來爆發許多重大金融弊案與風暴，使得公司治理的議題顯得相當重要。本研究以MSCI台灣指數成分股為研究對象，探討股權結構、董事會組成與超額報酬的關聯性，研究期間自2005年至2011年第二季為止。另以金融風暴事件為背景，觀察金融風暴前後公司治理與超額報酬間變動之關係。本文同時也將產業別列入考量，分析金融業與電子業的差異變化。 實證研究顯示：在股權結構方面，總樣本和電子相關產業的董監持股、大股東持股與股權偏離度對超額報酬呈正相關；經理人持股、法人持股對超額報酬呈負相關。而在金融產業部分，董監持股、經理人持股對超額報酬呈正相關。在董事會特性方面，在探究總樣本與金融業時，董事會規模、董事長兼任總經理、外部董監事比例、董監事質押比例對超額報酬均無顯著影響，在電子相關產業方面，外部董監事比例對超額報酬呈正相關，而董事會規模、董事長兼任總經理、董監事質押比例對超額報酬均無顯著影響。由此可知，股權結構是相較董事會組織更影響公司股價的超額報酬，因此投資人可先以股權結構的特性，為投資選擇的依據。 經金融風暴，電子相關產業與金融業之董監事持股比例由不顯著相關轉為顯著正相關，金融業之經理人持股由顯著正相關轉為不顯著。在董事會特性方面，電子相關產業與金融產業之外部董監事比例經金融風暴後皆由顯著正相關轉為不顯著相關。 The frequent occurrence of serious financial crisis has made the issue of corporate governance quite important in recent years. This study investigated the impact of the ownership structure, board composition on the excess return. The empirical samples are collected from stocks of MSCI Taiwan Index between 2005 and second season in 2011.Investigating the impact of the corporate governance on the excess return undergo the financial crisis. Empirical results in total samples and electronic companies how that the higher ratio of shares hold by board of directors and the major shareholders will increase the excess return, thehigher ratio of shares hold by managers and corporations will decrease the excess return. In financial companies, empirical results show that the higher ratio of shares hold by board of directors and the managers will increase the excess return. Otherwise, board composition didn’t impact the excess return in total sample and financial companies. Finally, ownership structure is more influence than board composition. After global financial crisis, shareholding of board in electronic companies and financial companies presentednot significant turned to significant positive effect on excess return.Shares hold by managers in financial companies presented significant positive effect turned to not significant on excess return. Outside directors presented significant positive effect in financial companies before global financial crisis, but it didn’t impact the excess return after global financial crisis.
